Electron discharge device



y 13, 1953 R. A. LEE 2,834,905

ELECTRON DISCHARGE DEVICE Filed March 28, 1956 IN V EN TOR.

Rbb erfA, Lee

A TTORNE Y United States Patent ELECTRON DISCHARGE DEVICE Robert A. Lee, Locust, N. J., assignor to Bendix Aviation Corporation, Eatontown, N. J., a corporation of Delaware Application March 28, 1956, Serial No. 574,430

3 Claims. (Cl- 313179) The present invention relates to gas filled electron dis? charge devices and more particularly to cold cathode gas filled diodes.

Heretofore, most cold cathode gas filled diodes, which utilized an oxide coated cathode, had a sprayed coating or a coating deposited by other suitable means on the cathode base metal before the device was assembled. Some of the disadvantages of the use of oxide coated cathodes are cathode damage due to positive ion bombardment, critical cathode activation procedures, the cathode activation spraying process, and the necessary care in drying, handling and storage. Further, with the generally used methods it is difiicult to activate a cathode so that it will function properly over a wide pressure range. This limits the tube characteristics.

The present invention eliminates the oxide coated cathode. Further, the present invention provides a much easier method of handling and storing the cathode surface material and a less critical means of obtaining a uniformly active cathode surface.

It is an object of the present invention to provide an improved gas discharge device.

Another object of the invention is to provide an im- I proved cold cathode gas filled diode.

Another object of the invention is to provide an improved method of coating cathodes.

Another object of the invention is to provide an improved method of activating cathodes.

The above and other objects and features of the invenfion will appear more fully hereinafter from a consideration of the following description taken in connection with the accompanying drawing, wherein one embodiment is illustrated by way of example.

In the drawing:

Figure l is a longitudinal sectional view of a device illustrating one embodiment of the invention.

Figure 2 is a sectional view of the device of Figure 1 taken along the line 2-2.

Figure 3 is an enlarged view of the barium filled rod of Figure 1.

Referring now to the drawing, a gas discharge device is indicated generally by the numeral 1 and includes a hermetically sealed envelope 2. The envelope 2 may be of glass or any other suitable material with base pins or terminals 3 sealed in the base and an exhaust tubulation 4 at its top. An arc-shaped cathode 5 is connected to 2,834,905 Patented May 13, 1958 and supported in the envelope 2 by a plurality of the base pins 3. The cathode 5 may be of a suitable material, such for example as nickel, with the concave face thereof uncoated. A rod like anode 6 is connected to and supported by one of the base pins 3. The anode 6 has a portion 7 formed to extend towards the concave face of the cathode 5.

Barium filled rods or ribbons 8 are supported substantially parallel to the cathode 5 by support members 9 and 10. The support members 9 and 10 are connected to and supported by respective base pins 3. The rods 8 may be of iron or any other suitable material and have a fiat portion 11 on one side thereof. The flat portion 11 is positioned to face the cathode 5 and provides a thin wall on the rod 8 to permit the evaporation of the barium filler.

In operation, after the device has been assembled, evacuated, baked and R. F. bombed, a current is passed through the rods 8 from the base pins 3 and support members 9 and 10. The current heats the rods 8 causing vaporization of the barium therein. The wall along the flat portion 11 breaks down, which permits the barium to escape and is'deposited on the cathode 5. A portion of the barium is also deposited upon the walls of the envelope and serves as the conventional getter. While a rod filled with barium has been illustrated and described, it is understood that other means could be used to provide free barium in the device for vaporization. Further, R. F. heating could be utilized to vaporize the barium.

Although only one embodiment of the invention has been illustrated and described, various changes in the form and relative arrangement of the parts, which will now appear to those skilled in the art, may be made without departing from the scope of the invention.

What is claimed is:

1. A gas discharge device comprising an envelope, an elongated concave shaped cathode, an inverted L-shaped anode, and barium filled rods supported substantially parallel to said cathode.

2. A gas discharge device comprising an envelope, an elongated cathode having a concave face, a rod like anode having a section thereof directed towards the concave face of said cathode, a ribbon supported on either side of said anode section, and an activating material in said ribbon facing said concave face of said cathode.

3. The combination 'as set forth in claim 2 in which said activating material is barium.

References Cited in the file of this patent UNITED STATES PATENTS 1,990,041 Loewe Feb. 5, 1935 2,217,205 Prescott Oct. 8, 1940 2,508,856 Cassman May 23, 1950 2,523,269 Back Sept. 26, 1950 2,657,452 Veenemans et a1. Nov. 3, 1953 2,680,206 Rich June 1, 1954 2,682,619 Landrey 1 June 29, 1954 

1. A GAS DISCHARGE DEVICE COMPRISING AN ENVELOPE, AN ELONGATED CONCAVE SHAPED CATHODE, AN INVERTED L-SHAPED ANODE, AND BARIUM FILLED RODS SUPPORTED SUBSTANTIALLY PARALLEL TO SAID CATHODE. 